In recent years, individual recognition technology has gotten a lot of attention. For example, there is a technology to be used for production and management, in which information such as a history of the object is clarified by giving an ID (an individual recognition number) to an individual object. Above all, the development of semiconductor devices that send and receive data without contact by using an electromagnetic field or a radio wave have been advanced. As such semiconductor devices, in particular, a wireless chip (also referred to as an ID tag, an IC tag, and IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, or an RFID (Radio Frequency Identification)) is beginning to be introduced into companies, markets, and the like.
Many of semiconductor devices that have been already been put to practical use have a circuit using a semiconductor substrate (also referred to as an IC (Integrated Circuit) chip) and an antenna, and the IC chip includes a memory and a control circuit.
In addition, depending on the structure of a memory provided in the IC chip, ways such as writing or reading of information are classified into various methods. For example, in the case of using a mask ROM for a memory circuit, no writing of data can be carried out other than in manufacturing the chip. In this case, no writing of data can be carried out other than in manufacturing the chip, and the chip is thus not user-friendly. Therefore, an ID chip in which data can be written other than in manufacturing the chip has been needed.
On the other hand, in the case of using an EEPROM or the like for a memory circuit, while a user can freely rewrite the content, some one other than the user is allowed to rewrite the information so that falsification is possible (for example, Non-Patent Document 1). Therefore, security measures are not implemented sufficiently now, and thus, measures that are able to prevent falsification by rewriting or the like have been needed.
In addition, an element has been needed, and active research and development are carried out actively.
(Non-Patent Document 1)
http://japan.cnet.com/news/sec/story/0,2000050480,20070122,00.htm